Place the fettuccine in the inner pot of the Instant Pot and fill with water to fully submerge the pasta. You may need to break the pasta in half to fit the liner.
Close the lid and turn the pressure valve to Sealing. Pressure cook on High for 7 minutes. Manually release the pressure when done. Remove the cooked pasta, drain and set aside.
Set the Instant Pot to Sauté. Add the butter and heat until melted.
After the butter has melted, add the garlic. Cook, stirring frequently, until fragrant (about 45 seconds). Add the cream and bring to a boil.
Once cream is boiling, add the grated Parmesan and seasonings. Stir to combine and cook for 3-5 minutes, stirring frequently, until desired thickness is achieved.
Serve Alfredo sauce over the cooked fettuccine and top with shredded Parmesan and chopped parsley if desired.
Notes
Add cooked chicken for an easy main dish meal. Rotisserie chicken works well.
Refrigerate leftovers in an airtight container for 2-3 days.